In the field of cathodic protection, corrosion of metallic structures is controlled by converting the metallic structure to be protected into a cathode of an electrochemical cell. There are passive and active systems. In a passive system, a more easily corroded sacrificial metal is employed as the anode (galvanic anode). In order for galvanic cathodic protection to work, the anode must possess a lower (that is, more negative) electrochemical potential than that of the cathode (the target structure to be protected). In this manner, the sacrificial metal of the anode corrodes instead of the protected metal. The passive system is employed on smaller structures, while larger structures, such as pipelines, require an active system. For larger structures, or where electrolyte resistivity is high, galvanic anodes cannot economically deliver enough current to provide protection. In these cases, impressed current cathodic protection (ICCP) systems are used. These consist of anodes connected to a DC power source, often a transformer-rectifier connected to AC power. Current flows between the anode and cathode, slowly corroding the anode and leaving the cathode un-corroded. Shunts are calibrated resistors used to measure current flow. These are hardwired into an impressed current cathodic protection system. While shunts are effective, they are difficult and time consuming to install. Often, additional structures are added and need to be protected. Expanding an impressed current cathodic protection system is made more difficult by the necessity of wiring in additional shunts.
It would be highly advantageous, therefore, to remedy the foregoing and other deficiencies inherent in the prior art.
An object of the present invention is to provide a shunt module for use in impressed current cathodic protection systems.